Correct! Mine was a 15/16 nut at least. Don't forget to heat it up before you attempt to remove it since it comes with red loctite on it. Also don't forget to install it with red loctite so it doesn't come off on ya later. Good luck man

and as me and Mike found out, not all tubers have the same pinion gear. 00+ bikes have a different gear than pre-00 bikes, so there are two different tools and you need to make sure you get the right one.